Apple will ban apps that warn drivers of DUI checkpoints, according to changes in the company's App Store Review Guidelines. The move comes four months after several U.S. senators called for the company to reject apps like Trapster and PhantomALERT that forewarn drivers of cops' roadblocks.

Millions of users have downloaded copies of such apps, but developers have denied that they're encouraging drunk driving; Trapster creator Pete Teneriello points to his app's "find a taxi" prompt as proof.

But is the genie out of the bottle? With such apps relying heavily on crowd sourcing for their information, it's possible the crowd will find their own way to thwart the rules by masking DUI checkpoints in code. Either way, the matter won't likely end here.